It is a standard practice in the industrialized world to disinfect the skin prior to any invasive procedure such as surgery, catheterization, or needle puncture to reduce the risk of infection. Decontamination of the oral cavity and nasal cavity also has been suggested to reduce the incidence of infection in cardiac surgery and/or to reduce spread of Methicillin Resistant Staphylococcus aureus (MRSA) in healthcare facilities. These products are often referred to as skin preps, nasal preps, oral preps, or simply “preps”. Recently there has been a number of papers published showing that patients who carry Staphylococcus aureus (SA) in their nose at the time of surgery are at much greater risk of acquiring a surgical site infection. It is particularly advantageous to customers to have a single product that can be used on both intact skin and mucosal tissue (e.g., vaginal, oral, nasal, and ocular tissue). Other sensitive tissues that antimicrobial products have been used on include acute and chronic wounds as well as burns.
Elemental (molecular) iodine (I2) has proven to be an outstanding antimicrobial agent for such antiseptic compositions. In many antiseptic compositions, iodine as antimicrobial agent is provided in solution in the form of an “iodophor” which is a complex of elemental iodine or triiodide with certain carriers. These iodophors function to not only increase the iodine solubility but to reduce the level of free molecular iodine in solution and to provide a type of sustained release reservoir of elemental iodine. Of available iodophors, povidone iodine is particularly useful.
Still other components have been shown to further boost the antimicrobial efficacy of elemental iodine. The addition of hydroxycarboxylic acids, for example, to antiseptic compositions as a buffer advantageously results in increased levels of bacterial “kill”. U.S. Pat. No. 7,147,873 (Scholz et al.) reports that elevated levels of hydroxycarboxylic acids (above 5% wt/wt) result in significantly improved antimicrobial efficacy. The use of hydroxycarboxylic acids in elevated levels in combination with iodophors like povidone iodine would thus seem rather desirable for most antiseptic compositions.